1. Field of the Invention
The present invention relates to a compound dobby machine used in a loom for weaving a dobby fabric, and particularly to an improvement of a hook connecting member in a chain disctype compound dobby machine.
2. Description of the Prior Art
A conventional chain disc-type compound dobby machine is shown in FIG. 6 as comprising upper and lower rocking hooks 51.sub.a and 51.sub.b as a fabric weave selecting mechanism supported on a machine base of a dobby machine, an upper hook 52.sub.a and a lower hook 52.sub.b connecting respectively with the upper and lower rocking hooks 51.sub.a and 51.sub.b, a chain 53 connecting the upper and lower hooks 52.sub.a and 52.sub.b, a jack lever 54 supported at the bottom thereof, and a rotating plate 55 pivoted nearly at the center of the jack lever 54. The chain 53 engages the rotating plate 55 whereby the upper hook 52.sub.a and lower hook 52.sub.b are moved linearly respectively by means of an upper knife 56.sub.a and a lower knife 56.sub.b in linear reciprocating motion so as to permit the jack lever 54 to be movable in a forward and backward rocking motion.
In recent years, the operating speed of dobby machines have been remarkably increasing in accordance with the high speed operation of looms. However, in a conventional compound dobby machine as shown in FIG. 6, parts which act according to instruction of the weave selecting mechanism 57, for example, the fish lever 58.sub.a and the rocking hook 51.sub.a, are mounted respectively on separate shafts 59.sub.a and 60.sub.a, or together on one shaft (not shown). Such fish lever 58.sub.a and rocking hook 51.sub.a are held in the connecting position by means of the springs 62.sub.a, 63.sub.a and transmit the action for the fish lever 58.sub.a to the rocking hook 51.sub.a according to instruction from the weave selecting mechanism 57 to displace the rocking hook 51.sub.a to which the hook 52.sub.a is connected in reciprocating motion by means of the knife 56. As above described, the fish lever 58.sub.a and the rocking hook 51.sub.a, both moved by the weave selecting mechanism 57, are separate structures, therefore the heavy weight decreases the efficiency for transmitting the motion according to instructions, particularly in high speed operation, and the moment of inertia increases tending to hinder the rotating speed.